Device for secure read, write and read/modify/write operation with divided track transducer head

Abstract

A method and apparatus for placing and later determining the distance between transitions from a first logical state to a second logical state stored on a medium, for example, a document. This determination is used to precisely characterize the information pattern in order to authenticate the information and the medium on which the information is stored. The invention uses a reader having a leading and trailing read apparatus, which allow information to be read simultaneously from two or more locations spaced a known distance apart. The distance between the center lines of each read apparatus is preferably an odd integer multiple of one half the distance between logical clock transitions. The distance between a first transition at the leading read apparatus and a next transition at the trailing read apparatus is used as a reference, hence given the term the “Reference Value”. The Reference Value is compared with the distance between the first transition and a second transition on the medium. Detection of deviations in spacing between transitions is unaffected by variations if the velocity of the medium with respect to the reader. Thus, the present invention is a method and apparatus for reading and writing conventional ISO 7816 data with additional precisely placed pulses that appear as noise to conventional reading apparatuses and as data to the described invention. In addition the present invention applies to a medium, which moves at an uncontrolled velocity relative to a read/write apparatus with which the data is read and written.

What is claimed is:  
     
       1. A device for secure read write, and read/modify/write operations comprising: 
       a first read head;  
       a second read head;  
       a return bar, common to both said first and second read heads, wherein said first read head and second read head are spaced apart by said common return bar;  
       wherein said common return bar is part of the same magnetic structure as said first and said second read heads and is employed as a writer head common to both said first and second read heads;  
       means for generating data variables for future use; and  
       means for storing said data variables in a memory for future use.  
     
     
       2. The device for secure read, write, and read/modify/write operations according to  claim 1 , wherein said cores of the first read head and of the second read are each constructed using a layer of ferrous material and a layer of non-ferrous material. 
     
     
       3. The device for secure read, write, and read/modify/write operations according to  claim 1 , further comprising: 
       means for generating an electronically readable serial number for future use; and  
       means for storing said electronically readable serial number in a memory for future use.  
     
     
       4. The device for secure read, write, and read/modify/write operations according to  claim 1 , further comprising one or more microprocessors containing stored data, for the purpose of secure transmission of said stored data. 
     
     
       5. The device for secure read, write, and read/modify/write operations according to  claim 4 , wherein said one or more microprocessors provide for encryption of the stored data, for the purpose of secure transmission of said encrypted stored data. 
     
     
       6. The device for secure read, write, and read/modify/write operations according to  claim 5 , wherein said device further includes a temperature sensor for monitoring operation of the device within a predetermined temperature range. 
     
     
       7. The device for secure read, write, and read/modify/write operations according to  claim 1 , wherein said first read head is spaced apart from said second read head by a multiple of ¾ wavelength of a bit cell. 
     
     
       8. The device for secure read, write, and read/modify/write operations according to  claim 7 , wherein said common return bar being employed as a write head, is used to place a short pulse on read media at a multiple of ¾ wavelength of a bit cell, and said first or second read heads are employed to detect said short pulse at a multiple of ¾ wavelength of a bit cell, whereby said short pulse detection is used to increase the amount of data stored on read media. 
     
     
       9. The device for secure read, write, and read/modify/write operations according to  claim 8 , wherein said device further includes one or more microprocessors containing stored data, for the purpose of secure transmission of said stored data. 
     
     
       10. The device for secure read, write, and read/modify/write operations according to  claim 9 , wherein said short pulse is used to verify the authenticity of the data. 
     
     
       11. The device for secure read, write, and read/modify/write operations according to  claim 1 , wherein said first read head is spaced apart from said second read head by a multiple of ½ wavelength of a bit cell. 
     
     
       12. The device for secure read, write, and read/modify/write operations according to  claim 11 , wherein said common return bar being employed as a write head, is used to place a short pulse on read media at a multiple of ½ wavelength of a bit cell, and said first or second read heads are employed to detect said short pulse at a multiple of ½ wavelength of a bit cell, whereby said short pulse detection is used to increase the amount of data stored on read media. 
     
     
       13. The device for secure read, write, and read/modify/write operations according to  claim 12 , wherein said device further includes one or more microprocessors containing stored data, for the purpose of secure transmission of said stored data. 
     
     
       14. The device for secure read, write, and read/modify/write operations according to  claim 13 , wherein said short pulse is used to verify the authenticity of the data. 
     
     
       15. A device for secure read, write, and read/modify/write operations comprising: 
       a first read head;  
       a second read head, wherein each read head acts as a leading read head or a trailing read head depending upon the direction of the media being read;  
       a return bar, common to the first read head and the second read heads and having a first end spaced apart from the first and from the second read heads and a second end joined to the first and second read heads, the return bar being part of the same magnetic structure as the first and the second read heads; and  
       means for recording and for comparing data, wherein a coincidence of read data is generated from said leading and trailing heads at random locations within the data recorded, said coincidence of read data is stored, and during a subsequent read operation a newly generated coincidence of read data is compared to said stored coincidence of read data for the purpose of verifying that the read data is not a forgery.  
     
     
       16. The device for secure read, write, and read/modify/write operations according to  claim 15 , wherein said first read head is spaced apart from said second read head by a multiple of ¾ wavelength of a bit cell. 
     
     
       17. The device for secure read, write, and read/modify/write operations according to  claim 15 , wherein the spacing between said first read head and said second read head is made slightly more or less than a multiple of ¾ wavelength of a bit cell, for the purpose of generating a positive or negative deviation for the bit spacing. 
     
     
       18. The device for secure read, write, and read/modify/write operations according to  claim 15 , wherein said first read head is spaced apart from said second read head by a multiple of ½ wavelength of a bit cell. 
     
     
       19. The device for secure read, write, and read/modify/write operations according to  claim 15 , wherein said the spacing between said first read head and said second read head is made slightly more or less than a multiple of ½ wavelength of a bit cell, for the purpose of generating a positive or negative deviation for the bit spacing. 
     
     
       20. The device for secure read, write, and read/modify/write operations according to  claim 2 , wherein one layer of said ferrous material in one read head is aligned with one layer of non-ferrous material in the other read head, and wherein the core of the return bar is composed of ferrous material and acts as a write head common to both read heads. 
     
     
       21. A method for secure reading, writing, and reading/writing/modifying operations on magnetic media, comprising the steps of: 
       (a) encoding data onto the magnetic media using a first read head, a second read head and a write head that are separated by shared read/write gaps and that are part of the same magnetic structure; and  
       (b) encoding offset transitions onto the magnetic media;  
       (c) storing information characterizing said offset transitions;  
       (d) reading the encoded data in (a) and detecting the presence of absence of said offset transitions stored;  
       (e) comparing the encoded data with the presence or absence of the offset transitions as detected in (d); and  
       (f) using the comparison to verify the authenticity of the read data on the magnetic media.  
     
     
       22. The method for securing reading, writing, and reading/writing/modifying operations in a data document according to  claim 21 , further comprising the steps of: 
       (a) using a first read head, a second read head and a common return bar acting as a write head to accurately measure the exact placement information of said encoded transitions;  
       (b) storing said exact placement information of said encoded transitions along with the presence or absence of said offset transitions; and  
       (c) comparing the exact placement of said transitions with the stored placement of said offset transitions during a subsequent read operation.  
     
     
       23. The method for secure reading, writing, and reading/writing/modifying operations in a data document according to  claim 21 , wherein the transitions are altered by encoding short pulses onto the magnetic media at about a ½ bit wavelength. 
     
     
       24. The method for secure reading, writing, and reading/writing/modifying operations according to  claim 21 , wherein the encoded data are altered by encoding offset transitions onto the magnetic media at approximately a ¾ bit wavelength. 
     
     
       25. A method for writing secure data on a magnetic medium and verifying the authenticity of a data document, comprising the steps of: 
       (a) encoding data onto magnetic media using a divided track transducer head having a first read head, a second read head and a write head that are separated by shared read/write gaps and that are part of the same magnetic structure; and  
       (b) encoding short pulses using said divided track transducer head;  
       (c) storing information generated by the encoding of said offset transitions;  
       (d) reading said encoded data and detecting the presence or absence of said offset transitions information previously stored;  
       (e) comparing the short pulses encoded in step (b) and the presence or absence of offset transitions information as detected if step (d); and  
       (f) using said comparison of said encoded offset transitions and the subsequently read offset transitions data to verify the authenticity of the data document.  
     
     
       26. The method for writing secure data on a magnetic medium data document and verifying the authenticity of a data document, according to  claim 25 , wherein the short pulses are encoded close to the ½ bit wavelength. 
     
     
       27. The method for writing secure data on a magnetic medium and verifying the authenticity of a data document, according to  claim 26  wherein said step of storing information generated by the encoding of said offset transitions further includes storing the exact placement information for said offset transitions encoded. 
     
     
       28. The method for writing secure data on a magnetic medium and verifying the authenticity of a data document, according to  claim 27  wherein said exact placement information for said offset transitions is compared with the exact placement of offset transitions in a subsequent read operation. 
     
     
       29. The method for writing secure data on a magnetic medium and verifying the authenticity of a data document, according to  claim 25  wherein said step of storing information generated by the encoding of said offset transitions further includes storing the exact placement information for said offset transitions encoded. 
     
     
       30. The method for writing secure data on a magnetic medium and verifying the authenticity of a data document, according to  claim 24  wherein said exact placement information for said offset transitions is compared with the exact placement of offset transitions in a subsequent read operation. 
     
     
       31. The method for writing secure data on a magnetic medium data document and verifying the authenticity of a data document, according to  claim 25 , wherein the short pulses are created close to the ¾ bit wavelength.